Many mental health problems involve a failure to apprehend accurately the nature of the social world, including the psychological properties of oneself and others. Moreover, the accurate judgment of personality is important for clinical diagnosis and practice, and has other practical implications. This proposal describes the continuation of a research program on the circumstances that make accurate judgment of personality more and less likely. Criteria for accuracy include agreement between judges and, increasingly in the next phase of this research, the ability of judgments to predict behavior. Possible influences on these criteria include the nature of the trait being judged, the nature of the behavior being predicted, and individual differences among the judges and the persons they judge. The next phase of this research will begin with the analysis of relationships between personality judgments and behavior within the large data set gathered during the initial phase. Two further studies will examine the accuracy of personality judgment according to multiple criteria. The first will be a longitudinal study of the effects of greater acquaintanceship on interpersonal judgment. The second will examine the accuracy of personality judgment in relation to behavior observed in increasingly diverse and realistic contexts. The ultimate goals of this research are a better understanding of the factors that make persons' judgments of themselves and each other more and less accurate, and a contribution to techniques for improving accuracy.